East Bethel closing old sewer treatment plant

The East Bethel City Council wants to shut down the Castle Towers wastewater treatment plant and move to a Metropolitan Council sewer treatment system in the northern part of the city.

The city cost is estimated to be $4.2 million to construct a second forcemain pipe from Viking Boulevard to the Whispering Aspen housing development area along the northern border of the city. Although the city and Metropolitan Council Environmental Services (MCES) already approved construction of a forcemain pipe to an area near 229th Avenue, this first forcemain could not have served northern East Bethel. Therefore, a second forcemain will be constructed to bring effluent from northern East Bethel south to the MCES wastewater treatment facility along 185th Avenue.

The city of East Bethel will be decommissioning the Castle Towers wastewater treatment plant, which serviced a mobile home park and the Whispering Aspen housing development. The city is working with Metropolitan Council to construct a forcemain to northern East Bethel to service these homes and land on the west side of Highway 65. Photo by Eric Hagen

Under the city’s plan, the Castle Towers mobile home park and the Whispering Aspen housing development would be served by the new sewer system instead of the city-operated Castle Towers wastewater treatment plant, which will be decommissioned because the city felt it was not worth renovating the 38-year-old system.

Existing Castle Towers and Whispering Aspen residents may or may not be assessed for the new MCES system. City Administrator Jack Davis said the council will further discuss funding options this spring. If the council is interested in assessing existing Castle Towers and Whispering Aspen residents starting in 2013, a public hearing would take place this summer.

In addition, the second forcemain opens up more land on the west side of Highway 65 to development opportunities. This development would help the city pay off the debt of the constructing the sewer and water system so that those who directly benefit from the system finance the system and not the general taxpayer base.

“Running the forcemain up to Castle Towers is going to give us more opportunities to generate ERUs than just what is in the current sewer project (area),” Councilmember Robert DeRoche Jr. said.

ERU stands for equivalent residential unit. This is a measuring system MCES uses when designing for the capacity of a sewer system. The typical single-family home counts as one ERU. A big box retailer typically counts as 40 ERUs, while a sit-down restaurant usually is 25 ERUs.

The council was unanimous in approving this option, although only Mayor Richard Lawrence and Councilmembers DeRoche and Steve Voss were at the March 21 meeting. Councilmembers Bill Boyer and Heidi Moegerle were absent.

Davis agrees with the decision the council made, he said.

“It gets us out of the sewer treatment business,” Davis said. “It wasn’t feasible for us to operate a small facility up there with a limited customer base.”

According to City Engineer Craig Jochum, the plan had been to have a gravity sewer system work its way up Highway 65, starting in southern East Bethel.

Jochum said it could have taken many decades to bring sewer to northern areas of the city on the west side of Highway 65 under this development system, but the new forcemain being discussed would eventually need to be replaced with a gravity sewer system although the forcemain could be sized bigger to handle more development before it needs to be replaced.

Although the forcemain would be going along the west side of Highway 65, a business or residential development cannot simply ask the city to hook a pipe into this forcemain to get sewer service.

Jochum said a lift station would need to be built to pump the sewer from the development to the forcemain. A developer would pay for the lift station, which is not cheap, so he said an individual gas station would likely not hook onto this sewer system by itself. It would take a large development to get a lift station built.

The city feels the most promising areas are between 209th and 221st avenues because there are large developable properties in that area, Davis said.

Money had to be spent

Davis and Jochum told the council that significant renovation work was needed at the Castle Towers wastewater treatment plant if the council chose to keep it and bypass the forcemain extension option. Staff calculated that about $1.6 million may have been needed to be spent in 2013 to replace the treatment tank and equipment, reconstruct the treatment building and to do some renovation to the polishing pond and the sludge drying bed.

There were a few other significant projects that would have had to take place over the next five years and would have brought renovation expenditures north of $1.8 million. In addition, the city would have needed to continue setting aside funds to operate the aging facility. Davis said they estimated it would have cost about $2.8 million to operate this facility over the next 30 years.

So even though the estimated $4.2 million capital cost to extend the forcemain is much greater than renovating the existing Castle Towers wastewater treatment plant, staff and the council looked 30 years down the road and determined that it was in the city’s best interest to decommission the Castle Towers plant.

Another factor that played a role in the decision is the city needs to allocate about $5.5 million toward construction of new sewer or water infrastructure. The former council in November 2010 issued $18,825,000 in bonds to cover the city’s sewer and water infrastructure costs. This happened after the election results showed that a new mayor and two new councilmembers would be part of the council starting in January 2011. These three — DeRoche, Lawrence and Moegerle — had asked the council at the time to delay its decision until after the new council was sworn in.

After delaying the whole project, the new council ultimately chose a different water treatment plant alternative that Jochum suggested would meet the needs of the city. Although the city saved money by selecting this cheaper water treatment plant option, the city is still obligated to allocate all the bond proceeds the former council approved.

In short, the water treatment plant savings will be used to finance this forcemain expansion project.